为了对传输管道半径24mm,电子束半径19mm,厚度3mm的环形电子束位置开展非阻拦测量,选择了BPM技术方案。对比研究了真空管道中环形电子束与位于束团中心的实心束在管道壁上产生的场分布,证明BPM测量技术可以用于电流密度均匀分布的环形电子束。采用点密度不均匀性模型,分析了环形电子束角向不均匀性对测量精度的影响。结果显示,当环形电子束电流密度不均匀性应为10%时,对位置分辨率精度的影响为0.1mm。 In order to carry out non-blocking measurement on the position of annular electron beam with 24mm radius, 19mm electron beam and 3mm thickness, BPM technology was selected. The field distribution of the annular beam and the solid beam in the center of the beam cluster on the pipe wall are compared and analyzed. It is proved that the BPM measurement technique can be applied to the annular electron beam with uniform current density distribution. The point density heterogeneity model is used to analyze the influence of the ring beam angular inhomogeneity on the measurement accuracy. The results show that the accuracy of the position resolution is 0.1 mm when the current density of the ring beam should be 10% non-uniform.